Few things inspire more terror in people than the idea that not only are we not alone, but that the bug-eyed monsters from the outer galaxies are buzzing cornfields in Kansas and picking up random chuckleheads and performing medical experiments on them. Who knows where that comes from, but ever since the Roswell incident, this has been a Going Concern for movies and television, H.G. Wells’ War of the Worlds notwithstanding.
These movies usually fall into two categories: The misunderstood monster, such as Gort from The Day the Earth Stood Still, or the confused being that doesn’t mean to hurt us (the Ymir from 20 Million Miles to Earth comes to mind). I like those movies, but that’s not what this list is about. This list is all about the scary stuff out there—the things that want to eat our faces, literally. There’s something deliciously thrilling when you combine the monstrous with the idea that it came from Out There, where we can’t go and can’t imagine what else might be waiting for us.